Emissions regulations for internal combustion engines have become more stringent over recent years. Environmental concerns have motivated the implementation of stricter emission requirements for internal combustion engines throughout much of the world. Governmental agencies, such as the Environmental Protection Agency (EPA) in the United States, carefully monitor the emission quality of engines and set emission standards to which engines must comply. Consequently, the use of exhaust aftertreatment systems on engines to reduce emissions is increasing.
Exhaust aftertreatment systems are generally designed to reduce emission of particulate matter, nitrogen oxides (NOx), hydrocarbons, and other environmentally harmful pollutants. However, the components that make up the exhaust aftertreatment system can be susceptible to the accumulation of various constituents such as particulate matter, ammonia, etc. Because the accumulation of, for example particulate matter, on the components may have adverse consequences on performance and the emission-reduction capability of the exhaust aftertreatment system, architecture of an exhaust aftertreatment system structured to detect and, if possible, correct such particulate matter is desirable.